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3 years ago

Anyone help me please?

Physics

1 answer:

choli [55]3 years ago

3 0

Answer:

I believe that its B my apologies if its wrong/

Explanation:

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2. A ball is thrown 45 m into the air. It takes the ball 5 s to hit the ground. What is the

koban [17]

Answer:

9m/s

Explanation:

45m÷5s=9m/s

Hope it helps!!!

6 0

3 years ago

Read 2 more answers

The driver of a 1750 kg car traveling on a horizontal road at 110 km/h suddenly applies the brakes. Due to a slippery pavement,

Alexeev081 [22]

Answer: a=-2.4525 m/s^2

d=s=190.3 m

Explanation:The only force that is stopping the car and causing deceleration is the frictional force Fr

Fr = 25% of weight

W=mg

W=1750*9.81

W=17167.5

Hence

$Fr=\frac{25}{100} * -17167.5\\\\Fr=-4291.875 N$

Frictional force is negative as it acts in opposite direction

According to newton second law of motion

F=ma

hence

$a=Fr/m$

$a=-4291.875/1750\\a=-2.4525$

given

u= 110 km/h

u=110*1000/3600

u=30.55 m/s

to get t we know that final velocity v=0

$v^2=u^2+2as\\0=30.55^2-2*2.4525*s\\s=190.34m$

3 0

3 years ago

A protostar's radius decreases by a factor of 100 and its surface temperature increases by a factor of two before it becomes a m

Sliva [168]

Answer:

$L_f = K (\frac{r}{100})^2 * (2T)^4$

$L_f = K \frac{r^2}{10000} * 16 T^4$

$L_f = \frac{16}{10000} k r^2 T^4 = \frac{1}{625} k r^2 T^4$

$L_f = \frac{1}{625} L_i$

So then we see that the final luminosity decrease by a factor of 625 so then the correct answer for this case would be:

B. Decreases by a factor of 625

Explanation:

For this case we can use the formula of luminosity in terms of the radius and the temperature given by:

$L_i = K r^2 T^4$

Where L_i = initial luminosity, r= radius and T = temperature.

We know that we decrease the radius by a factor of 100 and the temperature increases by a factor of 2 so then the new luminosity would be:

$L_f = K (\frac{r}{100})^2 * (2T)^4$

$L_f = K \frac{r^2}{10000} * 16 T^4$

$L_f = \frac{16}{10000} k r^2 T^4 = \frac{1}{625} k r^2 T^4$

$L_f = \frac{1}{625} L_i$

So then we see that the final luminosity decrease by a factor of 625 so then the correct answer for this case would be:

B. Decreases by a factor of 625

6 0

3 years ago

How is high temperature achieved by concave mirror?

tensa zangetsu [6.8K]

A concave mirror is used in the design of solar furnaces because they converge the parallel sunrays at a point. This helps to increase the temperature of the furnace.

3 0

3 years ago

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Which term describes the point when two objects reach the same temperature and there is no longer a transfer of energy through h

yaroslaw [1]

The term you need to know is equilibrium. Technically it means that heat gained = heat lost. Normally in beginning chemistry classes the evidence for this condition is a stable temperature.

5 0

3 years ago